飞轮微振动源机械扰振机理及耦合动力学特性研究

One of the key issues that restrict the development of satellites with high precision and superior performances in our country is the micro-vibration of flywheels. However, some attempts has to be made for better investigation of dynamic model and vibration control including the mechanism, the vibration transmission path, the coupling dynamic characteristics among the micro-vibration sources and the coupling dynamic characteristics between the flywheel and the outside loads. Therefore, the objective of the project is to solve the above problems. The mechanical mechanism of the micro-vibration will be investigated, and the dynamic model of the space precision bearing will be constructed. An analysis about the effects of microscale structural signatures, lubrication and space environmental properties will be carried out. Moreover, the coupling dynamic characteristics among the micro-vibration sources and the coupling dynamic characteristics between the flywheel and the outside loads will be established, and the effects of the structural and operational parameters on the coupling dynamic properties will be analyzed. A study of the transmission pass and the export micro-vibration properties will also be performed. The research work can not only provide a theoretical foundation for the optimization of the micro-vibration dynamic models, but also can improve the micro-vibration control technology, which will provide a theoretical support and technique storage for the solution of the flywheels micro-vibration.

飞轮微振动是制约我国高精度、高性能卫星发展的关键问题之一。目前飞轮微振动源的扰振机理尚不清晰，微振动的传递路径尚未明确，飞轮各微振动源之间以及飞轮与外部负载的耦合动力特性尚未掌握，直接限制了飞轮微振动建模技术和抑制技术的研究深度和有效性。因此，本项目拟探究飞轮微振动源的机械扰振机理，建立空间精密轴承的动力学模型，分析空间精密轴承的微观几何特征、润滑及空间环境特性对飞轮微振动特性的影响规律。建立飞轮微振动源与内部结构的耦合动力学模型及飞轮与外部负载的耦合动力学模型，研究结构参数和工作参数对耦合动力特性的影响规律，理清飞轮微振动的传递路径及输出特性。该项研究工作不仅可以作为微振动扰振模型技术的理论基础，而且能够指导微振动的抑制技术研究，为最终解决飞轮微振动问题提供理论支撑和技术储备。

以飞轮为代表的空间惯性执行机构是航天器平台姿态控制和精度保持的关键部件。飞轮高速旋转时产生的微振动是航天器平台的最大干扰源。随着航天器平台对高精度、高性能指标的不断提升，飞轮微振动成为制约我国高精度、高性能卫星发展的瓶颈问题之一。本项目从飞轮的结构特征和微振动源的扰振特性出发，剖析了飞轮微振动源的机械扰振机理，建立了微振动源与内部结构、飞轮与外部负载的耦合动力学模型。首先，基于Hertz接触理论和弹流润滑理论，建立了空间精密轴承的非线性精细动力学模型，掌握了空间精密轴承的几何特征、预载及转速等参数对空间轴承微振动特性的影响规律。与传统线性模型和位移协调模型相比，该模型可更准确地描述角接触球轴承中滚珠与滚道间的接触变形和接触角，得到更为准确的轴承非线性支承力。其次，考虑到不平衡量、转子系统陀螺效应和轴承非线性等，建立了飞轮微振动源与内部结构的耦合动力学模型，揭示了飞轮微振动源的机械扰振机理；考虑支承挠性, 建立了飞轮与外部负载的耦合动力学模型。最后，通过理论和试验对比分析，验证了耦合动力学模型的有效性，掌握了结构参数和工作参数对飞轮耦合动力学特性的影响规律, 理清了飞轮微振动的传递路径及输出特性。该项研究工作能够有效指导飞轮的减振设计及振动抑制技术研究，为最终解决飞轮微振动问题提供理论支撑。